A Mitochondrial Genome Phylogeny of Cleridae (Coleoptera, Cleroidea)

SIMPLE SUMMARY: The family Cleridae is a cosmopolitan group with approximately 4000 species and 320 genera. Within the family, the phylogenetic relationships among the subfamilies, and the timing of divergence, remain not yet fully resolved. Mitochondrial genomes have been widely used to reconstruct phylogenies of various insect groups, but never introduced to Cleridae until now. In this study, we newly generated 18 complete or nearly complete mitochondrial genomes, which are conserved in the organization and structure, as well as exhibit typical high A+T-bias and a preference of nucleotides A and G over T and C, as other insects. Further based on these sequences, a phylogeny of this family is reconstructed of different datasets by both maximum likelihood (ML) and Bayesian inference (BI) methods. The results are congruent and support the monophylies of the family and each subfamily, and the subfamilial relationships are recovered as Korynetinae + (Tillinae + (Clerinae + Hydnocerinae)). Moreover, a molecular clock analysis estimated the divergence time of Korynetinae from others no later than 160.18Mya (95% HPD: 158.18–162.06Mya). The current study presents the first mitochondrial genome-based phylogeny of Cleridae, which provides new evidence in reconstructing the phylogenetic relationships among the subfamilies and understanding the mitochondrial features of this family. ABSTRACT: The predaceous beetle family Cleridae includes a large and widely distributed rapid radiation, which is vital for the ecosystem. Despite its important role, a number of problems remain to be solved regarding the phylogenetic inter-relationships, the timing of divergence, and the mitochondrial biology. Mitochondrial genomes have been widely used to reconstruct phylogenies of various insect groups, but never introduced to Cleridae until now. Here, we generated 18 mitochondrial genomes to address these issues, which are all novel to the family. In addition to phylogenomic analysis, we have leveraged our new sources to study the mitochondrial biology in terms of nucleotide composition, codon usage and substitutional rate, to understand how these vital cellular components may have contributed to the divergence of the Cleridae. Our results recovered Korynetinae sister to the remaining clerids, and the calde of Clerinae+Hydnocerinae is indicated more related to Tillinae. A time-calibrated phylogeny estimated the earliest divergence time of Cleridae was soon after the origin of the family, not later than 160.18 Mya (95% HPD: 158.18–162.07 Mya) during the mid-Jurassic. This is the first mitochondrial genome-based phylogenetic study of the Cleridae that covers nearly all subfamily members, which provides an alternative evidence for reconstructing the phylogenetic relationships.